1. Field of the Invention
The invention relates to a connector producing method, a molding die and a connector with good fluid resistance.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. 2006-114245 and FIG. 9 herein disclose a connector to be installed in the body of a vehicle for grounding a part of a wiring harness circuit to the body. With reference to FIG. 9, a connector of this type includes a housing 140 molded with a terminal fitting 120 inserted therein. The terminal fitting 120 has first and second L-shaped bends 121, 122 to form a crank shape embedded in a resin of the housing 140. A tab 123 projects from the first L-shaped bend 121 and is connected with a terminal fitting of a mating connector (not shown). An installing portion 124 projects from the second L-shaped bend 122 and is fixed to a mounting part (not shown).
A connecting/separating force may be exerted upon inserting/withdrawing the mating connector and may concentrate on the second L-shaped bend 122 near the mounting part to which the terminal fitting 120 is fixed. Thus, the second L-shaped bend 122 may be deformed significantly and the deformation may cause the resin 141 of the housing 140 to crack.
The housing 140 of this connector is molded with a lower die 150 that has an upper opening edge and an upper die 160 that has a lower opening edge. The terminal fitting 120 is set in the lower die 150 so that the tab 123 of the terminal fitting 120 is inserted into a tab insertion hole 151 in the lower die 150 and so that the installing portion 124 of the terminal fitting 120 projects up. The upper die 160 then is lowered from above and the installing portion 124 of the terminal fitting 120 enters an installing-portion insertion hole 161. Insert molding then is performed. The respective insertion holes 151, 161 need to have a small clearance. Thus, the terminal fitting 120 that is to be molded in the housing 140 with the above-described molding die is in an unstable state and is slightly movable in the insertion holes when resin is injected into the molding die. As a result, the position of the terminal fitting 120 varies in the completed housing 140.
Japanese Unexamined Patent Publication No. H09-161866 shows another connector to be installed in the body of a vehicle for grounding a part of a wiring harness circuit to the body. The connector shown in Japanese Unexamined Patent Publication No. H09-161866 is formed by insert molding so that a terminal fitting penetrates through a synthetic resin housing. A small clearance may be formed between the terminal fitting and the resin due to a difference in coefficient of thermal expansion between the resin and the terminal fitting. Thus, a recess is formed in a wall where the terminal fitting is embedded, and a potting material is filled into the recess to seal the clearance between the terminal fitting and the resin if the connector is required to be water resistant.
The potting material is expensive and hence there is a demand for saving a filling volume as much as possible. On the other hand, the thickness of the terminal fitting is determined in view of required strength and cannot be made thinner than necessary. The diameter of the recess could be decreased to reduce the amount of potting material. However, a clearance between the opening of the recess and the outer periphery of the terminal fitting then becomes smaller, thereby reducing space for an injection nozzle to inject the potting material into the recess and significantly complicating the injection of the potting material. Specifically, the potting material may adhere to a connecting portion of the terminal fitting, thereby adversely affecting the connectability of the terminal fitting.
The terminal fitting could be thinned to ensure a sufficient insertion space for the injection nozzle. However, a thinner terminal is less rigid. The thin terminal fitting may deformed by forces generated while connecting/separating the connector or may be affected by the pressure of the injected resin during insert molding to vary its embedded position. Forces generated during curing shrinkage of the resin or potting material also may incline a thin terminal fitting in an unpredictable direction.
The invention was developed in view of the above, and objects thereof are to provide a connector producing method, molding die and connector to improve operability during manufacture, to prevent breakage of the resin covering a terminal fitting, to allow precise position of the terminal fitting and to allow easier injection of potting material.